CHIDI(3F)
CHIDI - CHIDI computes the determinant, inertia and inverse of a complex Hermitian matrix using the factors from CHIFA.
As shipped in IRIX 6.5.30. Unchanged since IRIX 6.5.
NAME CHIDI - CHIDI computes the determinant, inertia and inverse of a complex Hermitian matrix using the factors from CHIFA. SYNOPSYS SUBROUTINE CHIDI(A,LDA,N,KPVT,DET,INERT,WORK,JOB) DESCRIPTION On Entry A COMPLEX(LDA,N) the output from CHIFA. LDA INTEGER the leading dimension of the array A. N INTEGER the order of the matrix A. KVPT INTEGER(N) the pivot vector from CHIFA. WORK COMPLEX(N) work vector. Contents destroyed. JOB INTEGER JOB has the decimal expansion ABC where if C .NE. 0, the inverse is computed, if B .NE. 0, the determinant is computed, if A .NE. 0, the inertia is computed. For example, JOB = 111 gives all three. On Return Variables not requested by JOB are not used. A contains the upper triangle of the inverse of the original matrix. The strict lower triangle is never referenced. DET REAL(2) determinant of original matrix. Determinant = DET(1) * 10.0**DET(2) with 1.0 .LE. ABS(DET(1)) .LT. 10.0 or DET(1) = 0.0. INERT INTEGER(3) the inertia of the original matrix. INERT(1) = number of positive eigenvalues. INERT(2) = number of negative eigenvalues. INERT(3) = number of zero eigenvalues. Error Condition A division by zero may occur if the inverse is requested and CHICO has set RCOND .EQ. 0.0 or CHIFA has set INFO .NE. 0 . LINPACK. This version dated 08/14/78 . James Bunch, Univ. Calif. San Diego, Argonne Nat. Lab. Subroutines and Functions BLAS CAXPY,CCOPY,CDOTC,CSWAP Fortran ABS,CABS,CMPLX,CONJG,IABS,MOD,REAL